An aircraft gas turbine engine produces compressed air to be delivered to a combustor for combustion. Compressed air bled from the main source is delivered to various locations for other applications. For example, some aircraft require bleed air to be delivered to pressurize the aircraft cabin. In such a case, the bleed air, which has a relatively high temperature, must be cooled to a comfortable level for the passengers in the aircraft cabin. The compressed bleed air may be cooled outside of the gas turbine engine before it is introduced to the aircraft cabin. However, it is desirable to have such compressed bleed air cooled within the gas turbine engine.
Accordingly, there is a need to provide an improved bleed air cooling for a gas turbine engine.